ジャーナル: Nature / 年: 2023 タイトル: Cooperation between bHLH transcription factors and histones for DNA access. 著者: Alicia K Michael / Lisa Stoos / Priya Crosby / Nikolas Eggers / Xinyu Y Nie / Kristina Makasheva / Martina Minnich / Kelly L Healy / Joscha Weiss / Georg Kempf / Simone Cavadini / Lukas Kater ...著者: Alicia K Michael / Lisa Stoos / Priya Crosby / Nikolas Eggers / Xinyu Y Nie / Kristina Makasheva / Martina Minnich / Kelly L Healy / Joscha Weiss / Georg Kempf / Simone Cavadini / Lukas Kater / Jan Seebacher / Luca Vecchia / Deyasini Chakraborty / Luke Isbel / Ralph S Grand / Florian Andersch / Jennifer L Fribourgh / Dirk Schübeler / Johannes Zuber / Andrew C Liu / Peter B Becker / Beat Fierz / Carrie L Partch / Jerome S Menet / Nicolas H Thomä / 要旨: The basic helix-loop-helix (bHLH) family of transcription factors recognizes DNA motifs known as E-boxes (CANNTG) and includes 108 members. Here we investigate how chromatinized E-boxes are engaged ...The basic helix-loop-helix (bHLH) family of transcription factors recognizes DNA motifs known as E-boxes (CANNTG) and includes 108 members. Here we investigate how chromatinized E-boxes are engaged by two structurally diverse bHLH proteins: the proto-oncogene MYC-MAX and the circadian transcription factor CLOCK-BMAL1 (refs. ). Both transcription factors bind to E-boxes preferentially near the nucleosomal entry-exit sites. Structural studies with engineered or native nucleosome sequences show that MYC-MAX or CLOCK-BMAL1 triggers the release of DNA from histones to gain access. Atop the H2A-H2B acidic patch, the CLOCK-BMAL1 Per-Arnt-Sim (PAS) dimerization domains engage the histone octamer disc. Binding of tandem E-boxes at endogenous DNA sequences occurs through direct interactions between two CLOCK-BMAL1 protomers and histones and is important for circadian cycling. At internal E-boxes, the MYC-MAX leucine zipper can also interact with histones H2B and H3, and its binding is indirectly enhanced by OCT4 elsewhere on the nucleosome. The nucleosomal E-box position and the type of bHLH dimerization domain jointly determine the histone contact, the affinity and the degree of competition and cooperativity with other nucleosome-bound factors.